Cardiac Arrest – mechanical chest compressions, gender differences and coronary angiography

Abstract: Cardiac arrest is a major health problem with over 6000 cases of out-of-hospital cardiac arrest (OHCA) and 2500 cases of in-hospital cardiac arrest (IHCA) per year in Sweden. Survival are low. Many factors affect the chances of survival, including effective cardiopulmonary resuscitation and optimal post resuscitation care. These thesis involve these areas. Paper I+II describe a randomized clinical trial (n=2589). We compared a novel CPR algorithm with defibrillations during ongoing chest compressions delivered with a mechanical chest compression device and manual CPR according to guidelines. We found no difference in 4-hour survival, 23.6% with mechanical CPR and 23.7% with manual CPR. The vast majority of survivors in both groups had good neurological outcomes by 6 months. Paper III is a registry study (n=1498). We investigated impact of gender in performance and findings of early coronary angiography (CAG) and percutaneous coronary intervention (PCI), comorbidity and outcome among OHCA victims with an initially shockable rhythm. We found no difference between men and women in rates of ST-elevation/left bundle branch block (LBBB), 40% vs. 38% or rates of CAG, 45% vs. 40%. Among patients without ST-elevation/LBBB more men than women had CAG followed by PCI, 59% vs. 42% (P=0.03) and more advanced coronary artery disease. We found no association between gender and use of early CAG. Paper IV is a retrospective observational single centre study (n=423) of ICU treated victims of cardiac arrest. OHCA and IHCA were compared regarding comorbidity, characteristics of the arrest, treatment including CAG and CAG findings and outcome. OHCA patients had less preexisting comorbidity, lower rates of bystander CPR 71% vs 100% (p<0.001) and longer time to return of spontaneous circulation, 20 vs 10 minutes (p<0.001). OHCA patients more often had a shockable first rhythm, 47% vs 13% (p<0.001) and CA without any obvious non-cardiac origin, 77% vs 50% (p<0.001). OHCA patients more often underwent early CAG, 52% vs 25% (p<0.001) but no difference in rates of subsequent PCI or angiogram with at least one significant stenosis was seen. OHCA and IHCA did not differ in 30-days survival, 42% vs 41% or 1-year survival, 39% vs 33%